the question should be 'what was the dodo birds diet?'.

The tambalacoque, also known as the dodo tree, that's what them did eat like

Their diet consisted of fruit and they made their nests on the ground. The Dodo bird did not fly.

The tambalacoque, also known as the "dodo tree", was hypothesized by Stanley Temple to have been eaten from by Dodos, and only by passing through the digestive tract of the dodo could the seeds germinate; he claimed that the tambalacocque was now nearly extinct due to the dodo's disappearance. He force-fed seventeen tambalacoque fruits to Wild Turkeys and three germinated. Temple did not try to germinate any seeds from control fruits not fed to turkeys so the effect of feeding fruits to turkeys was unclear. Temple also overlooked reports on tambalacoque seed germination by A. W. Hill in 1941 and H. C. King in 1946, who found the seeds germinated, albeit very rarely, without abrading.[17][18][19][20]

from wiki.com

The dodo bird ate the Tambalacoque tree,also known as the "dodo tree". This is about the same question as "Did the dodo bird eat the dodo tree?" exept that it was more specific.

No. Prior to their extinction, dodos ate fallen fruit, especially that of the Tambalacoque tree, originally known by the scientific name of Calvaria major, but now renamed to Sideroxylon grandiflorum. It is also colloquially known as the "dodo tree".

Portuguese sailors said that they saw the Dodos eating fish. They also ate rocks and stones which might have helped them digest food.

Prior to their extinction, dodos ate fallen fruit, especially that of the Tambalacoque tree, originally known by the scientific name of Calvaria major, but now renamed to Sideroxylon grandiflorum. It is also colloquially known as the "dodo tree".
Portuguese sailors said that they saw the Dodos eating fish. They also ate rocks and stones which might have helped them digest food.